NEW ORLEANS — Patients with heart failure who also have hypoalbuminemia have a two- to threefold increased risk of death, compared with patients with normal serum albumin levels, according to results from a study in about 1,000 patients.
It's possible that this elevated mortality risk may be controlled using nutritional supplements or treatments aimed at cutting the inflammation associated with hypoalbuminemia, Tamara Horwich, M.D., said at the annual scientific sessions of the American Heart Association.
It's unclear what links hypoalbuminemia with worse survival during heart failure, but several candidate mechanisms exist. These include hemodilution, cardiac cachexia, biventricular heart failure, reduced colloid osmotic pressure causing pulmonary edema, and reduced tolerability and use of optimal medical therapy, said Dr. Horwich, a cardiologist at the University of California, Los Angeles.
Results from prior studies had linked hypoalbuminemia with a higher risk of death in a variety of disease states, including cancer, end-stage renal disease, infections, and cardiac surgery. But until now, few studies had examined whether a similar association exists in patients with heart failure.
To assess this potential link, Dr. Horwich and her associates reviewed case records for 1,162 heart failure patients with who were treated at UCLA Medical Center from December 1983 through June 2004. Some patients were excluded because their left ventricular ejection fraction was greater than 40% or they had inadequate follow-up. The study focused on the 1,039 eligible patients who remained. Their average age was 52 years, and their mean ejection fraction was 23%.
Patients were diagnosed with hypoalbuminemia if their serum albumin was less than 3.4 g/dL. About 25% of the patients in this study had hypoalbuminemia, a prevalence consistent with reports from prior studies of heart failure patients. Low albumin levels were most prevalent in lean patients, with a prevalence of 29%, but hypoalbuminemia was also common in overweight and obese patients, with prevalences of 15% and 20%, respectively.
The 1-year survival rate among patients who were hypoalbuminemic at baseline was 68%, compared with more than 80% for those with normal baseline serum albumin levels.
In a multivariate analysis that took into account a number of potential confounders, including age, gender, and body mass index, patients who had low serum albumin were 2.8-fold more likely to die, compared with patients with a serum albumin level within the normal range, Dr. Horwich said.